"""
Support for D-link W215 smart switch.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/switch.dlink/
"""
import logging
import urllib
from datetime import timedelta

import voluptuous as vol

import homeassistant.helpers.config_validation as cv
from homeassistant.util import dt as dt_util
from homeassistant.components.switch import (SwitchDevice, PLATFORM_SCHEMA)
from homeassistant.const import (ATTR_TEMPERATURE,
                                 CONF_HOST, CONF_NAME, CONF_PASSWORD,
                                 CONF_USERNAME, TEMP_CELSIUS)

REQUIREMENTS = ['pyW215==0.6.0']

_LOGGER = logging.getLogger(__name__)

DEFAULT_NAME = 'D-link Smart Plug W215'
DEFAULT_PASSWORD = ''
DEFAULT_USERNAME = 'admin'
CONF_USE_LEGACY_PROTOCOL = 'use_legacy_protocol'

ATTR_TOTAL_CONSUMPTION = 'total_consumption'

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_HOST): cv.string,
    vol.Required(CONF_USERNAME, default=DEFAULT_USERNAME): cv.string,
    vol.Required(CONF_PASSWORD, default=DEFAULT_PASSWORD): cv.string,
    vol.Optional(CONF_USE_LEGACY_PROTOCOL, default=False): cv.boolean,
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
})

SCAN_INTERVAL = timedelta(minutes=2)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up a D-Link Smart Plug."""
    from pyW215.pyW215 import SmartPlug

    host = config.get(CONF_HOST)
    username = config.get(CONF_USERNAME)
    password = config.get(CONF_PASSWORD)
    use_legacy_protocol = config.get(CONF_USE_LEGACY_PROTOCOL)
    name = config.get(CONF_NAME)

    smartplug = SmartPlug(host,
                          password,
                          username,
                          use_legacy_protocol)
    data = SmartPlugData(smartplug)

    add_entities([SmartPlugSwitch(hass, data, name)], True)


class SmartPlugSwitch(SwitchDevice):
    """Representation of a D-link Smart Plug switch."""

    def __init__(self, hass, data, name):
        """Initialize the switch."""
        self.units = hass.config.units
        self.data = data
        self._name = name

    @property
    def name(self):
        """Return the name of the Smart Plug, if any."""
        return self._name

    @property
    def device_state_attributes(self):
        """Return the state attributes of the device."""
        try:
            ui_temp = self.units.temperature(int(self.data.temperature),
                                             TEMP_CELSIUS)
            temperature = ui_temp
        except (ValueError, TypeError):
            temperature = None

        try:
            total_consumption = float(self.data.total_consumption)
        except (ValueError, TypeError):
            total_consumption = None

        attrs = {
            ATTR_TOTAL_CONSUMPTION: total_consumption,
            ATTR_TEMPERATURE: temperature,
        }

        return attrs

    @property
    def current_power_w(self):
        """Return the current power usage in Watt."""
        try:
            return float(self.data.current_consumption)
        except (ValueError, TypeError):
            return None

    @property
    def is_on(self):
        """Return true if switch is on."""
        return self.data.state == 'ON'

    def turn_on(self, **kwargs):
        """Turn the switch on."""
        self.data.smartplug.state = 'ON'

    def turn_off(self, **kwargs):
        """Turn the switch off."""
        self.data.smartplug.state = 'OFF'

    def update(self):
        """Get the latest data from the smart plug and updates the states."""
        self.data.update()

    @property
    def available(self) -> bool:
        """Return True if entity is available."""
        return self.data.available


class SmartPlugData:
    """Get the latest data from smart plug."""

    def __init__(self, smartplug):
        """Initialize the data object."""
        self.smartplug = smartplug
        self.state = None
        self.temperature = None
        self.current_consumption = None
        self.total_consumption = None
        self.available = False
        self._n_tried = 0
        self._last_tried = None

    def update(self):
        """Get the latest data from the smart plug."""
        if self._last_tried is not None:
            last_try_s = (dt_util.now() - self._last_tried).total_seconds()/60
            retry_seconds = min(self._n_tried*2, 10) - last_try_s
            if self._n_tried > 0 and retry_seconds > 0:
                _LOGGER.warning("Waiting %s s to retry", retry_seconds)
                return

        _state = 'unknown'
        try:
            self._last_tried = dt_util.now()
            _state = self.smartplug.state
        except urllib.error.HTTPError:
            _LOGGER.error("Dlink connection problem")
        if _state == 'unknown':
            self._n_tried += 1
            self.available = False
            _LOGGER.warning("Failed to connect to dlink switch.")
            return
        self.state = _state
        self.available = True

        self.temperature = self.smartplug.temperature
        self.current_consumption = self.smartplug.current_consumption
        self.total_consumption = self.smartplug.total_consumption
        self._n_tried = 0
